Drilling holes in walls

[PB1]

Hi all
I am wanting to fit an extractor fan in a kitchen wall. The spec says it needs a hole 173mm in diameter, but the diamond core drill bit sets I see for sale at the usual places only seem to go up to 152mm. Any advice or alternative suggestions please? Thanks

 

[telectrix]

you would need a powerful drill for that size try the hire companies for the drill and the corer.

 

[Rockingit]

Can i suggest you double check that number against the real thing with a tape measure?? Because if it's been typo'd or spanglished then it could actually be anything!!!

 

[PB1]

Thanks Rockingit. Trouble is I haven't bought a fan yet as it's for a customer. I've seen some other more expensive fans which say they need a 152mm hole, which seems to be a standard size of diamond core bits. I've never drilled a hole like this before although I have been told it takes a while. I'll have a look at the hire company route like telectrix suggests because I don't want to knacker my sds drill doing it!

 

[Rockingit]

still sounds like a really odd size for an extractor - metricated versions of 4,5 & 6 inch are most common - 7" is quite odd these days and you'll also struggle to find extract duct, grills etc. I've just had a quick look through the vent catalogues on my desk and there's nothing that size being listed at all. It might be a lot less hassle just to find an alternative fan!!!

 

[telectrix]

a 6" fan is about 150mm, so the 152mm looks more likely. you need to get the fan before drilling a hole that's the wrong size

 

[PB1]

Yes I think you are correct. I don't want to buy a non standard bit size, even if I could get one, so will choose a fan that will definately fit in a 152mm hole. Thanks for your help.

 

[Octopus]

Are you sure you need a 6" fan? Would a 4" fan do??

 

[VoltzElectrical]

dont buy an expensive bit for one job. hire the drill and bit.

 

[Spudnik]

Are you sure you need a 6" fan? Would a 4" fan do??

It depends on the room size and extraction rate in m3/hr.

I fitted a 5" fan in the wall of a massive kitchen a couple of years ago.

However, its was specified in the plans.

 

[Pat Tester]

It's not always necessary to use a diamond / core drill. draw the hole on the wall and chain drill around using a smaller
drill 8 - 10mm I find best. Of course you do need to be able to drill in a straight line.

 

[Geordie Spark]

you would need a powerful drill for that size try the hire companies for the drill and the corer.

I agree.

If you're thinking of driving a bit this size with an SDS I think you'll end up wrecking the SDS.

The alternative method is chain drilling a series of holes in a circle slightly bigger than the diameter that you want then drilling a series of holes within that circle, & getting stuck in with your hammer & chisel.

The more material you remove with the drill the less bashing with the hammer & chisel you have to do !!

 

[Dunc]

Just rent a 6inch core cutter from Travis Perkins or similar. They'll rent you a core drill too which is designed for the job but if you're doing holes in house hold brick and block then any 4kg SDS drill will eat through no problem. I've done a 6inch hole before in limestone with a 36V Bosch SDS before, took a lot of batteries to go through but that was better then stringing out a 400m extension lead to get to the rear of the house! Fans in kitchens have to be able to shift 60l/s if not making up part of an extractor hood (which has to shift 30l/s). You can get some centrifugal fans that will do 60l/s through a 100mm duct but they're usually big units and expensive to come by. Manrose do a 150mm fan that will do 64l/s for under £30+VAT. Just Google '60l/s fan' and you'll find one easily.

 

[Mark_Burgess]

Where are you based, maybe someone on here might drill it for you for a cost similar to the hire cost?